Horticulture Section, College of Agriculture, Banaras Hindu University
*Present address: Department of Horticulture, J. N. Agricultural University. Jabalpur, M. P.
Effect of five concentrations of iron applied as 0, 1, 2, 3 and 4 ppm on pineapple was studied under sand nutrient culture. Iron was applied as foliar spray in the form of ferrous sulphate. Height of plant, total root extension, fresh and dry weights of roots was significantly influenced by 3 ppm of iron spray. Leaf area, fresh and dry weights of leaves and plants showed significant response with 4 ppm of iron spray. Iron application at 3 ppm improved nitrogen and crude fibre contents in the leaves. It also improved phosphorus, total carbohydrate, C/N ratio and ash contents at 4 ppm concentration. Potassium content in the leaves was highest in iron deficient plant. Net assimilation rate was highest with I ppm iron at 265 days stage, 4.ppm iron at 458 days stage and with 1 ppm at 916 days stage of the plant life. Useful responses of iron at 4 ppm concentration were obtained as early flowering, early maturity of fruits and shortening the total period of cropping. Percentage of fruiting was noted to be 100 per cent with 4 ppm of iron spray. Fresh and dry weights of fruit, percentage of edible portion in the fruit and specific gravity were appreciably improved with 4 ppm. Highest reducing, non-reducing and total sugars, water soluble acidity, Vitamin C, total soluble solids and ash contents in the fruit were noted by 4 ppm of iron application. Crude fibre content in the fruit was noted to be minimum with 4 ppm of iron application.
